电动汽车绝缘电阻有源检测系统.pdf

第27卷第5期
电子测量与仪器学报
Vol 27 Na.5
2013年5月
JOURNAL OF ELECTRONIC MEASUREMENT AND NSTRUMENT
409
D01:10.3724/SP.J.1187.2013.00409
电动汽车绝缘电阻有源检测系统
周晨胡社教沙伟2刘勤勤'俞秀文1
合肥工业大学计算机与信息学院合肥230001.安徽江淮汽车技术中心电控技术部合肥2300
摘要:针对目前电动汽车绝缘电阻检测方法的缺陷,以改进式乒乓式变电桥检测法为基础,提出了一种新型的有源检
测方法。该方法从正负母线帯电和不帯电2种情况来分析新方法绝缘电阻检测的工作过程,通过注入高压直流电压信号,
在电池开路的情况下亦能检测高压电路与车体之间的绝缘性能,同时也克服了传统直流系统绝缘检测方法中正负母线对
地对称绝缘故障无法测量的问题,进一步提高了检测精度。最后,通过实验检测证明,绝缘电阻检测精度有所提高,误差
控制在.5%以内,符合预期目标。
关键词:直流系统;绝缘电阻;乒乓式变电桥;有源检测
中图分类号:TM855文献标识码:A国家标准学科分类代码:470.4037
Active detection system of insulation resistance in electric vehicle
Sha Weiliu Qin
(1. School of Computer Information, Hefei University of Technology, Hefei 230009
2. lectronic Control Technoloey Dept Anhui Jianguai Automobile Technology Center, Hefei 230009, China)
Abstract: Aiming at the defects of the traditional insulation detection method, a new type of active detection meth
is pro
Bed, which is based on the modified measurement of ping-pong variable bridge. The new method ana
zes how to detect the insulation resistance in both bus charged and uncharged eases. This method is suitable to de
tect the insulation performance between the high voltage circuit and the car body by high voltage DC signal injection
in the case of open circuit and also can be used effectively under the situation of positive and negative bus symmet-
ric insulation fault, which cannot be solved using traditional passive insulation resistance detection method. At last,
the experimental test shows that the insulation resistance test accuracy is improved, and the error is controlled with
in 5%, which meets the desired goal
Keywords: DC system; insulation resistance; ping-pong variable bridge; active detection
1引言
漏电流回路,使底盘电位上升,不仅会危及乘客的
人身安全,还将影响低压电器和车辆控制器的正
电动汽车的动力系统是一个高电压、大电流常工作山。由于电池组的电压通常在300V以上,
的电路,在正常情况下,高压系统是一个封闭的系它的绝缘问题会给电动车辆的驾驶员和乘客造成
统,对车体完全绝缘,但不排除由高压电维老化等人身危险,应于以特別重视。
问题带来的绝缘降低使车体漏电,且电动汽车T
传统的电桥式绝缘检测2只能检测单端绝缘
作环境复杂,振动、温度和湿度急剧变化,酸碱气破坏情况,这种平衡桥法不受接地电容的影响,检
体的腐蚀,都会引起绝的损伤和破坏,使绝缘性测速度快,但当正负两端绝缘同时下降时,不能发
能下降。电源正、负极引线通过绝缘层和底盘构成现并报警。而低频信号注入法虽可以检测双极
接地,但是注人的低频信号增加了直流电压的纹
收稿日期:2012-12 Received Date:2012-12
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